With constant improvement of performance of a computer system, power consumption becomes increasingly higher. In most situations, however, low power consumption and processing capabilities are sufficient to meet a user's work requirement, for example, document editing, music playing, network browsing, etc. High processing speed and power consumption requirement are needed only in some infrequent special situations, e.g., running a large-scale 3D game, high-quality image or video processing, etc. Therefore, in most cases, a computer system may provide excessively high processing capabilities to the user, resulting in unnecessary power consumption and waste of energy resources. For a computer system using battery as power supply, such as a laptop computer, this will lead to a non-ideal duration of battery, and even affect the user's normal operation in some severe situation.
In order to address the above problem, a power supply management scheme is generally employed to set a plurality of states, such as dormancy, sleep and standby, for the computer system, and different power supply schemes are used in the respective states. For example, screen luminance is reduced during music playing, or a processing speed of CPU is lowered when during document edition.
The above scheme, however, has disadvantages in that there is no significant reduction in the overall power consumption of the computer system, because the CPU is still running despite its lowered processing speed, and a mainboard chip set, a memory, a hard disk and the like are also still in an operating state. In fact, the power consumption of CPU accounts for only about 10% of the overall power consumption of the system, while the mainboard chip set of a main board, the internal memory and the like, which are running in a normal manner, consume a primary part of the electric power.
Various manufacturers of fitting parts consider performance improvement and power consumption reduction as one of main targets when developing new products. Although great progress has been made in this aspect, there is rarely some solution in terms of an overall technique of the computer system.